I read with great interest the article on “Bevacizumab or laser for aggressive posterior retinopathy of prematurity” (APROP) by Blair et al.[1] and would like to congratulate the authors for the study. The authors have concluded that unfavorable structural outcomes are more common in initial laser-treated eyes as compared to eyes treated initially with bevacizumab.

However, a few points need to be answered. The authors did not categorize the outcomes with respect to zones of involvement. Although classically APROP is seen in Zone I, it can be seen in posterior Zone II as well.[2] Zone I again can be categorized into anterior or posterior. Was there any preponderance of zone I posterior eyes in laser group? Studies have shown poor outcomes in the zone I ROP, especially in postzone I disease.[3] Moreover what were the predictors of unfavorable outcome in this study? Did they have any preretinal hemorrhage before treatment or early-onset fibrovascular proliferation just after laser photocoagulation, which has been cited as poor predictors in APROP despite laser in literature.[4] I agree with the authors that overall smaller gestational age of the cohort may be one of the reasons of relatively higher unfavorable outcome with a laser as compared to other studies. It will also be interesting to know if any of the eyes in laser group showed any skip areas during reactivation and needed treatment with supplemental laser photocoagulation.

Out of 22 eyes who were initially managed with injection, a significant proportion had reactivation of disease and ultimately majority received laser photocoagulation at different timeframes. Hence, relatively better favorable outcome of injection arm is probably due to combination modality rather than injection alone.

As also quoted in index study, Lorenz et al. have described a single dose of 0.312 mg bevacizumab was efficient to induce regression of ROP in posterior Zone II and most of Zone I cases, but not in aggressive posterior ROP.[5] Various safety concerns of bevacizumab in premature infants in the form of unknown optimal dosage, neurodevelopmental issues, high reactivation rate, systemic vascular endothelial growth factor suppression, the risk of crunch phenomenon have been aptly described by the authors.[1] Considering all these factors, combined intravitreal bevacizumab and zone I sparing laser may be an effective treatment option for zone I ROP; however using bevacizumab as a primary modality of treatment in all infants of APROP warrants caution and needs to be validated by larger randomized trials.

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Conflicts of interest

The authors declare that there are no conflicts of interests of this paper.